Traffic monitoring for coordinated traffic management—Experiences from the field trial integrated traffic management in Amsterdam

In the first phase of the large-scale field trial integrated traffic management in Amsterdam (acronym: PPA), a hierarchical control approach is used to coordinate the algorithms of the ramp metering installations along a densely used freeway corridor with the intersection controllers along one of the connecting urban arterials. This hierarchical control approach requires a similarly organised hierarchical monitoring approach. This approach is based on several freeway and urban state estimation and prediction techniques. In this contribution we describe and discuss two of these in terms of their underlying rationale and we give some some examples of their application. In the final part of this paper we discuss a number of critical issues that came up in the implementation of these methods in the PPA. These relate to the difficulty of communicating the underlying scientific ideas into practice. They also relate to the fact that some of the underlying (scientific) puzzles have not yet been solved.